一个linux上注册的led类打印设备及操作方法

1、一个在PC上注册的led类打印设备及操作方法/*leds_w380.c*/include include #include #include include linux/string#includc #includc #includc 严* Blue led.* (it can only be blue flashing led)*/static void w38O_blueled_set(struct Ied_classdev *lcd_dcv, enum Ied_brightness value)s3c_gpio_cfgpii】(S5PV210_GPJ3(4), S3C_GPIO_SFN(

2、2); /s3c_gpio_setpull(S5PV210_GPJ3(4), 0);switch (value) case LED_HALF:s3c_gpio_sctpin(S5PV210_GPJ3(4), 1); printk(Mw3801eds_onnH);break:case LED_FULL:s3c_gpio_sctpin(S5PV210_GPJ3(4), 1); printk(Mw3801eds_oniiH);break:default:case LED_OFF:/s3c_gpio_setpin(S5PV210_GPJ3(4), 0);primk(”v7w3801cds_offn”)

3、；break;static ssizej w380_blue_show(struct device *dcv,struct device_attribute *attr, char *buf)struct lcd_classdcv *bled =container_of(dev,stnict lcd_classdc：dcv );/w380_blueled_set(bled)； return sprintf(buf, ,r%unM, 0);static ssizej w380_blue_store(struct device *dev, struct deviceattribute *attr,

4、 const char *buf, sizej count)struct lcd_classdcv *blcd =container_of(dev,stnict lcd_classdcv.dcv );w380_bluelcd_set(bled.255);return 0;static DEVICE_ATTR(bIue, 0644、w380_bluc_show, w380_blue_store);static stnict attribute *w3801ed_attributes = & dev_attr_blue.attr.NULLstatic stnict attribute_group

5、w3801ed_attribute_group = ars = w3801ed_at tributesstatic stnict led_classdev w380_blueIed = .name= Hw38O:blue.brightness_set= w380_blueled_set,;*/static int w3801eds_probe(stnict platforni_device *pdcv)int ret;printk(Hw3801eds_probenM);ret = Ied_classdev_register(&pdcvdcv, &w380_blueled);if (ret)go

6、to err_blue; printk(Hw380Ieds_probe_device_create_fiIenH);/ret = device_create_file(&pdev-dev, &dev_attr_blue);/ret = sysfs_creatc_group(&pdcvdcv.kobj, &w3801ed_attribute_group); printk(,w3801eds_probe_device-create-file00000nn);if (ret != 0)dev_err(&pdcvdcvNo source control for LED: %dnM, ret);retu

7、rn 0;err_blue:dev_err(&pdcvdcv, lcd_classdcv_rcgislcr failednM); printk(Hw3801eds_probefaiIednH);lcd_classdev_unregister(&w380_blueled);static int w3801eds_remove(struct platform_device *pdev)led_classdev_unregister(&w380_bluclcd);return 0;static stnict platforni_driver w3801eds_driver = .driver= .n

8、ame= Mw380Jeds*.owner= THIS_MODULE.,.probe= w3801eds_probe,.remove= w3801cds_rcmovc,；static stnict platform_device w3801cds_dcvicc = .name = Hw380Jeds；static int _init w3801edsjnit(void)printk(ww3801edsJnitnH);printk(uw3801edsJnitnH);int ret;ret=platforin_driver_register(&w3801cds_drivcr);if(!ret) p

9、rintk(Hplatforni_dcvice_registerir,);ret = platform_device_register(&w3801eds_device);if (ret)printk(,platform_driver_unregisternu); platform_driver_unregister(&w3801eds_driver);)return ret;static void exit w3801cds_exit(void)printk(Hw3801eds_exitnM);platform_device_register(&w3801cds_dcvicc); platf

10、orm_driver_unregister(&w3801eds_driver);module_init(w3801edsjnit);module_exit(w3801eds_exit);MODULE_AUTHOR(Hwang tao H);MODULE_DESCRIPTION(MLED driver for the w38OH);M0DULE_LICENSE(9PLJ;MODULE_ALIAS(Mplatform:w380Jedsn);其Makefile文件如下：注意命令的开头是一个tabifneq ($( KERNELRELEASE),)#kbuild syntax. dependency

11、relationshsip of files and target modules are listed here.mymodule-objs := leds_w380.oobj-m := leds_w380.oelsePWD := $(shell pwd)KVER ?= $(shell uname -r)KDIR := /lib/modules/$(KVER)/buildall:$(MAKE) -C $(KDIR) M=$(PWD)clean:rm -rf *.cmd *.o *.mod.c *.ko .tmp_versions end if步骤一：编译，make 一下生成lcds_w380

12、.o和lcds_w380ko等步骤二:复制，将 lcds_w380.ko 复制至iJ/lib/module/2.6.32-21 -generic/kernel/drivers/leds F 步骤三：加载 sudo modprobe lcds_w380Sudo rmmod lcds_w380.koSudo insmod lcds_w380.ko这样反复的目的是利用modprobe的依赖关系。00 lxxulinux: -/shares/test/iedFile Edit View Terminal Helplxxulinux:$ cd shares/test/led/ lxxjlinux：/sh

13、ares/test/leds make make -C /lib/modules/2.6.32-21-generic/build M=/home/lxx/shares/test/led makel: Entering directory /usr7src/liniixheaders26.32-2generic1cc M /home八xx/shares7test/led/leds_w380o /home/lxx/shares/te5t/l.ed/leds_w380. c: In function 4w3801ed5_init *: /home/lxx/shares/test/led/leds_w

14、380.c:140: warning： ISO C90 forbids roixed declar ations and code/home/lxx/shares/test/led/leds_w380.c: In function w380leds_probe： /home/lxx/shares/test/led/leds_w380.c：112: warning： control reaches end of non oid functionBuilding modules, stage 2MODPOST 1 modulesCC /home/lxx/shares/test/led/leds_w

15、38D.mod.oLD M /home/lxx/shares/test/led/leds2w389.koleds_w380 onodules.orderMakefileModule syroversleds w380.ko leds jv380.mod.c leds w380.mod.o lxxaulinux：Vshares/test/leds c/kernel/drivers/leds/ sudo password for Ixx： ixxulinux：-/shares/test/leds lxxjlinux:/shaes/test/leds lxxulinux：-/shares/test/

16、ledsmakel: Leaving directory /usr/src/linux-headers-2.5.32-21-generic lxxulinux:-/shares/testAedS Is built-in.oMakefile.bakcp leds_w380.ko /lib/modules/2.6.32-21-generileds_w38e.csudosudo sudo sudoleds w386.c.bakmodprobe leds_w38 rmnod leds_w380.ko insmod leds w380.kolxxulinux：-/shares/test/leds |步骤

17、四：成功验证,Sudo lsmodRxxulinux：*/shares/test/led$ IsDuilt-in.oledsw380.koleds w336.cledsw380.mod.cleds w38G.c.bak leds w380.mod.o Lxxulinux：-/shares/test/led$ sudoc/kernel/drivers/leds/sudo password for Ixx： lxxulinux:*/sha res/test/led$ lxxulinux：-/shares/test/led$ lxxulinux：Vshares/test/led$ lxx(aulin

18、ux：*-/shares/test/led$Leds_w380 omodules o rderMakefileModule symversMakefile.bakcp leds_w380.ko /lib/modules/2.6.32-21-generiModule leds w380 ledclass vsock vmmenic tl vmblock i/mci vmhgfs pvscsiSize17452864370707296 10766 26826 48805 11732sudo modprobe leds w380 sudo rnmod Leds_w380.ko sudo insnri

19、od leds_w38G ko sudo IsmodUsed by01 leds w3800e11 vsock10以下是测试代码：/*ledtest.c*/#includc #include #include /include /#include #define DEVNAME 7sys/class/leds/w38O:blue/brightnessH /*需要注意的是这个宏可以针对操作不同的设备而修改*/ static int writejnt(char const* path, int value)int fd;static int already.warned = 0;fd = open

20、(path. O_RDWR);if (fd = 0) char buffer20;int bytes = sprintf(buffer, M%dnn, value); printf(Hbuffer:%sn, buffer);int amt = write(fd buffer, bytes);close(fd);return amt = -l ? 1: 0; else if (already_warned = 0) printf(Mwrite_int failed to open %sn”，path); already_warned = 1;)return -1;int main(int arg

21、c, char *argv)int turn;检测命令后而带的参数if(argc = 1 II argc 2)printf(uUsage: Led onloff!nM); exit(l);判断输入的参数if(strcmp(argvl, HonH) = 0)turn = 255; printf(uUsage: Led on!nH);else if(strcmp(argvl, off1) = 0)turn = 0;printf(uUsage: Led off!nN);elseprintf(uUsage: Led onloff!nM); exit(l);write_int(DEVNAME.turn)

22、;return 0;进入lcdtest g录，编译生成ledtest执行/ledtest on0 0 0 lxxulinux: /sl Browse the World Wide WebFile Edit view Terminal Helpmptscsih313251 mptspimptbase830222 mptspi,mptscsihfloppy530160scsi transportspi210961 mptspivmxnet154180lxx(aul.inux:-/shares/test/led$ cd . lxxulinux:/shares/test$ Iscmd.txt H le

23、dtest ledtest.c ledtest.c.bak Makefile Makefile.bak lxxulinux：/shdes/test$ nakeMakefile：l： * commands commence before first target Stop lxx(aulinux:Vshares/test$ gcc -o ledtest ledtestc lxxulinux：-/shares/test$ /ledtest onUsage： Led on!writeint failed to open /sys/class/leds/w380:blue/brightness lxx

24、ulinux:-/shares/test$ sudo /ledtest onUsage： Led on!buffer：255lxxulinux:*/shares/test$ sudo ./ledtest off Usage： Led off!buffer：lxxulmux:-/shares/test$执行dmesg查看结果:O O lxxulinux: -*/shares/testFile Edit View Iferminal Help=691 n ame=,7usr/lib/cups/backend/cups-pdf,18.336168 type=i505 audit(1293694211.023：1引：operaTion=*profile_IoadM pid=691 nafne=M /usr/sbin/cupsdn8.38